(function(){
	// stackBlur
    var mul_table = [
        512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,
        454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,
        482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,
        437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,
        497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,
        320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,
        446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,
        329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,
        505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,
        399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,
        324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,
        268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,
        451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,
        385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,
        332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,
        289,287,285,282,280,278,275,273,271,269,267,265,263,261,259];
        
   
    var shg_table = [
         9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 
        17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19, 
        19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
        20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
        21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
        21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 
        22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
        22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 
        23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24 ];

    function stackBlurCanvasRGB( canvas, width, height, radius, top_x, top_y, callback){
        if ( isNaN(radius) || radius < 1 ) return;
        radius |= 0;
        
        var context = canvas.getContext("2d");
        var imageData;
        
        try {
          try {
            imageData = context.getImageData( top_x, top_y, width, height );
          } catch(e) {
          
            // NOTE: this part is supposedly only needed if you want to work with local files
            // so it might be okay to remove the whole try/catch block and just use
            // imageData = context.getImageData( top_x, top_y, width, height );
            try {
                netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
                imageData = context.getImageData( top_x, top_y, width, height );
            } catch(e) {
                console.log("Cannot access local image");
                //throw new Error("unable to access local image data: " + e);
                return;
            }
          }
        } catch(e) {
          console.log("Cannot access image");
          //throw new Error("unable to access image data: " + e);
        }
                
        var pixels = imageData.data;
                
        var x, y, i, p, yp, yi, yw, r_sum, g_sum, b_sum,
        r_out_sum, g_out_sum, b_out_sum,
        r_in_sum, g_in_sum, b_in_sum,
        pr, pg, pb, rbs;
                
        var div = radius + radius + 1;
        var w4 = width << 2;
        var widthMinus1  = width - 1;
        var heightMinus1 = height - 1;
        var radiusPlus1  = radius + 1;
        var sumFactor = radiusPlus1 * ( radiusPlus1 + 1 ) / 2;
        
        var stackStart = new BlurStack();
        var stack = stackStart;
        for ( i = 1; i < div; i++ ){
            stack = stack.next = new BlurStack();
            if ( i == radiusPlus1 ) var stackEnd = stack;
        }
        stack.next = stackStart;
        var stackIn = null;
        var stackOut = null;
        
        yw = yi = 0;
        
        var mul_sum = mul_table[radius];
        var shg_sum = shg_table[radius];
        
        for ( y = 0; y < height; y++ ){
            r_in_sum = g_in_sum = b_in_sum = r_sum = g_sum = b_sum = 0;
            
            r_out_sum = radiusPlus1 * ( pr = pixels[yi] );
            g_out_sum = radiusPlus1 * ( pg = pixels[yi+1] );
            b_out_sum = radiusPlus1 * ( pb = pixels[yi+2] );
            
            r_sum += sumFactor * pr;
            g_sum += sumFactor * pg;
            b_sum += sumFactor * pb;
            
            stack = stackStart;
            
            for( i = 0; i < radiusPlus1; i++ ){
                stack.r = pr;
                stack.g = pg;
                stack.b = pb;
                stack = stack.next;
            }
            
            for( i = 1; i < radiusPlus1; i++ ){
                p = yi + (( widthMinus1 < i ? widthMinus1 : i ) << 2 );
                r_sum += ( stack.r = ( pr = pixels[p])) * ( rbs = radiusPlus1 - i );
                g_sum += ( stack.g = ( pg = pixels[p+1])) * rbs;
                b_sum += ( stack.b = ( pb = pixels[p+2])) * rbs;
                
                r_in_sum += pr;
                g_in_sum += pg;
                b_in_sum += pb;
                
                stack = stack.next;
            }
            
            
            stackIn = stackStart;
            stackOut = stackEnd;
            for ( x = 0; x < width; x++ ){
                pixels[yi]   = (r_sum * mul_sum) >> shg_sum;
                pixels[yi+1] = (g_sum * mul_sum) >> shg_sum;
                pixels[yi+2] = (b_sum * mul_sum) >> shg_sum;
                
                r_sum -= r_out_sum;
                g_sum -= g_out_sum;
                b_sum -= b_out_sum;
                
                r_out_sum -= stackIn.r;
                g_out_sum -= stackIn.g;
                b_out_sum -= stackIn.b;
                
                p =  ( yw + ( ( p = x + radius + 1 ) < widthMinus1 ? p : widthMinus1 ) ) << 2;
                
                r_in_sum += ( stackIn.r = pixels[p]);
                g_in_sum += ( stackIn.g = pixels[p+1]);
                b_in_sum += ( stackIn.b = pixels[p+2]);
                
                r_sum += r_in_sum;
                g_sum += g_in_sum;
                b_sum += b_in_sum;
                
                stackIn = stackIn.next;
                
                r_out_sum += ( pr = stackOut.r );
                g_out_sum += ( pg = stackOut.g );
                b_out_sum += ( pb = stackOut.b );
                
                r_in_sum -= pr;
                g_in_sum -= pg;
                b_in_sum -= pb;
                
                stackOut = stackOut.next;

                yi += 4;
            }
            yw += width;
        }

        
        for ( x = 0; x < width; x++ ){
            g_in_sum = b_in_sum = r_in_sum = g_sum = b_sum = r_sum = 0;
            
            yi = x << 2;
            r_out_sum = radiusPlus1 * ( pr = pixels[yi]);
            g_out_sum = radiusPlus1 * ( pg = pixels[yi+1]);
            b_out_sum = radiusPlus1 * ( pb = pixels[yi+2]);
            
            r_sum += sumFactor * pr;
            g_sum += sumFactor * pg;
            b_sum += sumFactor * pb;
            
            stack = stackStart;
            
            for( i = 0; i < radiusPlus1; i++ )
            {
                stack.r = pr;
                stack.g = pg;
                stack.b = pb;
                stack = stack.next;
            }
            
            yp = width;
            
            for( i = 1; i <= radius; i++ )
            {
                yi = ( yp + x ) << 2;
                
                r_sum += ( stack.r = ( pr = pixels[yi])) * ( rbs = radiusPlus1 - i );
                g_sum += ( stack.g = ( pg = pixels[yi+1])) * rbs;
                b_sum += ( stack.b = ( pb = pixels[yi+2])) * rbs;
                
                r_in_sum += pr;
                g_in_sum += pg;
                b_in_sum += pb;
                
                stack = stack.next;
            
                if( i < heightMinus1 )
                {
                    yp += width;
                }
            }
            
            yi = x;
            stackIn = stackStart;
            stackOut = stackEnd;
            for ( y = 0; y < height; y++ )
            {
                p = yi << 2;
                pixels[p]   = (r_sum * mul_sum) >> shg_sum;
                pixels[p+1] = (g_sum * mul_sum) >> shg_sum;
                pixels[p+2] = (b_sum * mul_sum) >> shg_sum;
                
                r_sum -= r_out_sum;
                g_sum -= g_out_sum;
                b_sum -= b_out_sum;
                
                r_out_sum -= stackIn.r;
                g_out_sum -= stackIn.g;
                b_out_sum -= stackIn.b;
                
                p = ( x + (( ( p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1 ) * width )) << 2;
                
                r_sum += ( r_in_sum += ( stackIn.r = pixels[p]));
                g_sum += ( g_in_sum += ( stackIn.g = pixels[p+1]));
                b_sum += ( b_in_sum += ( stackIn.b = pixels[p+2]));
                
                stackIn = stackIn.next;
                
                r_out_sum += ( pr = stackOut.r );
                g_out_sum += ( pg = stackOut.g );
                b_out_sum += ( pb = stackOut.b );
                
                r_in_sum -= pr;
                g_in_sum -= pg;
                b_in_sum -= pb;
                
                stackOut = stackOut.next;
                
                yi += width;
            }
        }
        
        context.putImageData( imageData, top_x, top_y );
        
        if(callback) callback();
    }

    function BlurStack(){
        this.r = 0;
        this.g = 0;
        this.b = 0;
        this.a = 0;
        this.next = null;
    }

    $.fn.stackBlur = function(opts){
    	return this.each(function(){
    		opts = $.extend({
    			radius: 0,
    			styles: {
    				position: 'absolute',
    				left: 0,
    				top: 0
    			}
    		}, opts);

    		var img = opts.img,
    			canvas = document.createElement('canvas'),
    			_this = this,
    			w = img.width,
    			h = img.height;

    		canvas.width = w;
			canvas.height = h;

			$(_this).append(canvas);
			$(canvas).css(opts.styles);

			var context = canvas.getContext("2d")
			context.clearRect(0, 0, w, h );
	    	context.drawImage(img, 0, 0 );

	    	if(opts.radius < 1) return;

	    	stackBlurCanvasRGB(canvas, w, h, opts.radius, 0, 0, opts.callback);
    		
    	});
    }
})();